BULLETIN No. 52

STATE OF ILLINOIS DEPARTMENT OF REGISTRATION AND EDUCATION A. M. SHELTON, Direclor

DIVISION OF THE STATE GEOLOGICAL SURVEY M. M. LEIGHTON, Chief

BULLETIN No. 52

PENNSYLVANIAN FLORA OF NORTHERN ILLINOIS

PRINTED BY XCTHORTTY OF THE STATE OF ILLISOIS STATE OF ILLINOlS DEPARTMENT OF REGISTRATION AND EDUCATION A. M. SHELTON, Divect3v

DIVISION OF THE STATE GEOLOGICAL SURVEY M. M. LEIGHTON, Chief

Committee of the Board of Natural Resources and Conservation

A. M. SHELTON,Chaiman Director of Registration and Education

KENDRICC. BABCOCK Representing the President of the University of Illinois

EDSONS. BASTIN Geologist PREFACE During parts of the field seasons of 1905, 1906, and 1907, the Illinois Geological Survey had the valued services of America's dean of Carbonifer- ous paleobotany, Dr. David White, in a general reconnaissance of the Upper Coal Measures, now precisely referred to as the Pennsylvanian system. Previous to that time but little work had been done, chiefly by Leo Lesquereux from collections by A. H. Worthen and associates. White's work led to a general correlation of the strata of the Illinois coal field with the eastern field, and to a division of the Pennsylvanian system into three series: the Pottsville (lowest), the Carbondale, and the McLeansboro. In 1921, in connection with an intensive study of the coal resources of Illinois, the State Geological Survey undertook a program of a more detailed study of the plant forms found in strata associated with the coal beds, fully realizing that the facts to be uncovered by such an investigation would likely be of inestimable value to a proper correlation of the coal beds in different parts of our State and to our knowledge of their extent and relationships. The work is being conducted by Dr. A. C. Noit, Asso- ciate Professor of Paleobotany of the University of Chicago, and has already reached an advanced stage. The study is far-reaching in its relations to the functions of the Geolog- ical Survey, to the proper identification of coal beds which the Survey uses in determining the existence of favorable structures for the commercial occurrence of oil and gas, to the estimates made of the State's coal resources, to the scientific contributions which the Survey is in position to make on both the character of the vegetation, climatic environ- ment, and physiographic conditions of the Pennsylvanian period, and on the life history of the plant kingdom, and finally, with unneglected atten- tion, to providing secondary schools and colleges of the State with desir- able educational material. It is designed eventually to publish a comprehensive monograph on the flora of the Pennsylvanian system of Illinois, properly illustrated and containing descriptions of both old and new species, and the conclusions to be drawn regarding coal correlations. The field, however, is very extensive, and, in order that advantage may be taken of data obtained in the course of the study, short bulletins covering sub-units of the State will be issued. The present bulletin is an account of the Pennsylvanian flora of northern Illinois, marking the completion of the work of one of the sub- units. Its treatment is feasibly popular, and such technical descriptions as new and old species may require are left for the monograph.

State Geological Survey,

PENNSYLVANIAN FLORA OF NORTHERN ILLINOIS

By A . C . No6

OUTLINE

PARTI PAGE Introduction ...... 9 General statement ...... 9 Location and brief description of localities ...... 9 Collections ...... 10 Historical review ...... 10 Method of determination ...... 11 Organization of the nlaterial ...... 11 Acknowledg~nent~...... 12 Identification of fossiPplants ...... 12 Definition of a fossil plant species ...... 12 List of figured species ...... 13 Discussion of figured orders and genera ...... 15 Equisetales ...... 15 Sphenopl~yllales...... 16 Lycopodiales ...... 16 Filicales ...... 16 Cycadofilicales ...... 18 Cordaitales ...... 18

a Explanation of Plates 1.XL.V ...... 19 ILLUSTRATIONS PLATE PAGE I Reconstruction of swamp forest in Pennsylvanian time . After H . Potoni6. 20 I I Equisetales from La Salle and Braidwood regions ...... 22 111 Equisetales from Mazon Creek and Braidwood regions ...... 24 IV Equisetales from Morris and Mazon Creek regions ...... 26 v Equisetales from Mazon Creek and Braidwood regions ...... 28 v I Sphenophyllales from Mazon Creek and Braidwood regions ...... 30 VI I Lycopodiales from Nlazon Creek region ...... 32 VIII Lycopodiales from Braidwood and Mazon Creek regions ...... 34 IX Lycopsdiales from Mazon Creek region ...... 36 X Lycopodiales from Mazon Creek region...... 38 XI Lycopodiales from Braidwood region ...... 40 XI1 Lycopodiales from Braidwood ...... 42 XI I I Filicales: Sphenopteridae from Braidwood and Mazon Creek regions .... 44 XIV Filicales: S~henopteridaefrom Mazon Creek region ...... 46 XV Filicales: Megalopteridae from Port Byron ...... 48 XVI Filicales: Mariopteridae from NIazon Creek and Braidwood regions ..... 50 XVI I Filicales: Neuropteridae from Spring Valley and Mazon Creek regions . . 52 XVIII Filicales: Neuropteridae from Mazon Creek and Braidwood regions ..... 54 XIX Filicales: Neuropteridae from Braidwood region ...... 56 XX Filicales: Neuropteridae from NIazon Creek region ...... 58 XXI Filicales: Neuropteridae from Mazon Creek region ...... 60 XXI I Filicales: Neuropteridae from Mazon Creek region ...... 62 XXIII Filicales: Neuropteridae from l\/lazon Creek ...... 64 XXIV Filicales: Neuropteridae from Mazon Creek and Braidwood regions ..... 66 XXV Filicales: Neuropteridae from Braidwood and Mazon Creek regions .... 68 XXVI Filicales : Neuropteridae from Mazon Creek region ...... 70 XXVII Filicales: Neuropteridae from Mazon Creek and Braidwood regions ..... 72 XXVI I I Filicales: Various fern leaf types from Mazon Creek region ...... 74 XXIX Filicales: Pecopteridae from Mazon Creek region ...... 76 XXX Filicales: Pecopteridae from Mazon Creek region ...... 78 XXXI Filicales: Pecopteridae from Mazon Creek region ...... 80 XXXII Filicales : Pecopteridae from Braidwood region ...... 82 XXXI I I Filicales : Peco~teridaefrom Morris region ...... 84 XXXIV Filicales: Pecopteridae from Mazon Creek region ...... 86 . XXXV Filicales: Pecopteridae from Mazon Creek region ...... 88 XXXk71 Filicales: Pecopieridae from Mazon Creek region ...... 90 XXXVI I Filicales: Odontopteridae from Mazon Creek region ...... 92 XXXVI I I Filicales: Alethopteridae from Mazon Creek and Braidwood regions ..... 94 XXXIX Filicales: Alethopteridae from Mazon Creek region ...... 96 XL Filicales: Alethopteridae from Mazon Creek region ...... 98 XLI Filicales: Calli~teridaefrom Mazon Creek region ...... 100 XLII Cycadofilicales: Reproductive organs. From NIazon Creek region ...... 102 XLIII Cycadofilic&les: Reproductive organs. From NIazon Creek and Braid- woodregions ...... 104 XLIV Cycadofilicales and Cordaitales: Reproductive organs . From Braidwood and Mazon Creekregions ...... 106 XLV Cycadofilicales, Cordaitales, and fern stems from NIazon Creek, Braid- woodand Coal City ...... 108

PART I.-TEXT

INTRODUCTION

The Coal Measures, or the Pennsylvanian system, of Illinois lie in the heart of the Eastern Interior Coal Field which extends from southeastern Iowa on the northwest to western Indiana on the east, and from upper Illinois River on the north, to western Kentucky on the south. By far the greater part of this great coal field is in Illinois. The strata reach a maximum thickness of about 2,000 feet in southern Illinois, and contain at least five distinct commercial "veins" or beds of coal of varying extent, besides a number of local beds. As these are largely covered by later Coal Measures strata and glacial drift, the number of exposures are relatively small. Consequently, the question of the areal extent and relationships of these beds rests upon the identification of the beds by certain characteris- tics, one of which, and a very important one, is the different species and genera of fossil plants associated with each coal bed.

The fossil flora herein set forth was collected from the so-called No. 2 coal bed of District 1 in northern Illinois. One of the main localities where such plants have been collected are the mine dumps northeast of Braidwood in Will County. The majority of plants from concretions and all the Braid- wood plants from shale were collected at the Skinner No. 2 mine two miles northeast of the Chicago and Alton Railroad station at Braidwood in the NW. of Sec. 4, T. 32 N., R. 9 E. in Will County. Two other localities where only concretions are found at present are at the so-called Ox Bow of the Mazon River, seven and ten miles southeast of Morris, located in the NW. of Sec. 30 and the NE. of Sec. 24, T. 33 N., R. 7 E. of Grundy County. Formerly considerable quantities of fossil plants were also collected in the shale above the coal in various small mines north of Morris, but almost all these mines are now shut down. The Wilmington Star No. 7 mine in the NE. % of Sec. 5, T. 33 N., R. 8 E., 2% miles west of the Santa F6 depot in Coal City, also supplied some fossils. Another locality which still produces fossil plants from the shale above the coal is the No. 1 mine of the Spring Valley Coal Company at Spring Valley, in the SW. of Sec. 35, T. 16 N., R. 11 E. in Bureau County. The Skinner No. 2 mine shaft is 60 feet deep to the coal. The fossils are contained in concretions extending through about six feet of shale above the coal and excellent impressions are found directly in the shale, not more than twelve inches from the coal. No concretions were observed in the coal in Wilmington Star No. 7 and in the Spring Valley No. 1 mines. The fossils there are foulid only in the shale. The coal lies in the Wilming- 9 10 PENNSYLVANIAN FLORA OF NORTHERN ILLINOIS

ton Star mine at an average of 135 feet below the surface, except near the main shaft, where it is 185 feet deep. At Spring Valley the coal lies 360 feet below the surface. The coal seams associated with shales carrying fossil plants are commonly called No. 2 coal in Illinois, with the local name of the "Third Vein" at La Salle and Spring Valley. For the sake of convenience, the No. 2 designation will be kept in this bulletin, although a later correlation of coal seams on the basis of fossil plants in Illinois may suggest a different number. The flora which is described from these localities is somewhat analogous to the flora of the Stephanian of Germany and France, which would indicate a stratigraphic position much higher than that of the lower Carbondale.

The material which is described in this bulletin was collected partly by the author and his students, and part of it is in other existing collections. The most prominent collectors during the latter part of the nineteenth century and of the present time were C. D. Young, J. C. Carr, and L. E. Daniels, all of Morris, Illinois; W. J. Knoblock, of Quincy, Illinois, and George Condie, of Spring Valley. The mine management of the Wilming- ton Star No. 2 mine also contributed a valuable specimen for this description. Mr. C. D. Young of Morris has donated his extremely valuable collection to the University of Chicago. The Carr and Daniels collections were acquired by the University of Illinois and are kept in the Museum of Natural History, Urbana, Illinois. Mr. Knoblock's collection is in his home at Quincy, but a portion of it was generously lent to the University of Chi- cago for a period of time in order to be described. The collection of Mr. Condie is in his home in Spring Valley. The author wishes to express his appreciation of the assistance which he has received from Mr. F. C. Baker, Curator of the Natural History Museum, University of Illinois, who not only facilitated the study of the collection at the Museum but lent a portion of it for a specified time to the University of Chicago.

The literature describing the fossil flora of northei-n Illinois belongs to the later decades of the nineteenth and the first of the twentieth century. Volume 2 (1866) and Volume 4 (1870) of the first Geological Survey of Illinois contain numerous descriptions of fossil plants by Leo Lesquereux, the Swiss naturalist who arrived in the United States as the companion of Louis Agassiz. He was destined to become the father of paleobotany in this country, while Sir William Dawson inaugurated the same science in Canada. Lesquereux collected all available information on fossil plants of the American Carboniferous formation for Report P of the Second Geologi- cal Survey of Pennsylvania published under the title, Coal Flora of the Carbon

Volume 3, containing text and some plates, in 1884. A great many of Lesquereux's fossil plants were described again and in a few instances aug- mented by other species in a Dictionary of the Fossils of Pennsylvania and Neighboring States, compiled by J. P. Lesley (Geological Survey of Penn- sylvania Report P 4, 1889-1890). Another publication which contains illustrations and descriptions of Carboniferous plants of North America based upon determinations by Lesquereux is North American Geology and Paleontology for the Use of Amateurs, Students and Scientists, by S. A. Miller, Cincinnati, 1889. These books contain the earlier investigations of fossil plants of the Pennsylvanian in Illinois and nothing more was done along these lines until the years 1906, 1907, and 1908, when a new era of Paleozoic plant studies was inaugurated in Illinois by David White, Geologist of the United States Geological Survey, upon instigation of the State Geological Survey of Illinois. Dr. White's observations are given in Bulletins 4, 8, and 14 of the Illinois State Geological Survey. He restricted himself to a preliminary report of the distribution of Pennsylvanian plants in Illinois. It was on the basis of his observations that the subdivisions of the Pennsylvanian system in Illinois-Pottsville, Carbondale, and McLeansboro-were made. A new and third period in the study of fossil plants in Illinois began when the State Geological Survey engaged the services of the author for extensive collecting of Pennsylvanian plants throughout the State. These collections will be described in a series of reports of which this one is the first.

All specimens of the collection were first checked against the figures of Lesquereux's Atlas of the Coal Flora of Pennsylvania. They were also compared with the Carboniferous specimens described and illustrated in the works of David White, R. Zeiller, A. Renier, C. Grand'Eury, B. Renault, H. Potonii., W. Gothan, and W. J. Jongmans. Lesquereux's nomenclature is obsolete and needs frequent corrections so that many of the species have now been relegated to the class of synonyms. His nomenclature was, therefore, corrected with the help of the above- mentioned authors and by comparing them with the species' names and synonyms listed in the catalogue of the Paleozoic plants in the Department of Geology and Paleobotany of the British Museum, by R. Kidston, London, 1886, and in the manuscript catalog of David White.

The organization of paleobotanic material is not as simple a matter as would be the arrangement of a living flora. The taxonomic and the biologic points of view for the classification of fossil plants frequently do not agree, and yet a purely artificial system of plants cannot be considered the ideal basis for organizing such material. Therefore, the author 12 PENNSYLVANIAN FLORA OF KORTHERN ILLINOIS has kept in mind the biologic considerations as they are expounded in the most recent general paleobotanic textbooks such as the following: Seward, A. C. : Fossil Plants, 4 vol., London, 1898-1919. Berry, E. W.: Paleobotany, a Sketch of the Origin and Evolutio~zof Floras, Washington, 1920. Potonie, H. and 117. Gothan: Lehrbuch der Paleobotanik, 2nd edition, Berlin, 1921. Scott, D. H.: Studies in Fossil Plants, 3rd edition, London, 1921-23. Got han, W.: Leitfossilien-Karbon und Perm. P-flanzen,Berlin, 1923. Scott, D. H.: Extinct Plants and Problems of Evolution, London, 1924.

The author wishes to express his sincere thanks to D. C. Young, the donor of a beautiful collection of fossil plants from the Mazon Creek deposits to the University of Chicago; to Ed. Carr, son of the collector, J. C. Carr, for many courtesies and numerous fossils given to the University of Chicago; to F. C. Baker, Curator of the Natural History Museum, University of Illinois, for his great kindness in facilitating the study of the Carr and Daniels collections; to W. J. Knoblock in Quincy and George Condie in Spring Valley for the loan of valuable fossils; to Dr. W. E. Walsh in Morris for specimens and valuable assistance; and to W. Oswald of Braidwood for his courtesy and help. The deepest gratitude of the author is felt toward the State Geological Survey of Illinois which has facilitated and published these studies. Special thanks are also due to the former Chief of the Survey, Mr. F. W. DeWolf, and to the present Chief, Dr. M. M. Leighton, who authorized and generously supported these investigations. The author is much indebted to Dr. Harold E. Culver, who was in charge of the coal investigations of the Illinois State Geological Survey and who gave invaluable aid throughout the investigation. To Dr. David White, who has critically read this report and offered most valuable suggestions, the author wishes to express his sincere appreciation. IDENTIFICATION OF FOSSIL PLANTS

In order to identify and classify fossil plants, it is important to have in mind what a fossil species is. It is more difficult to distinguish fossil plant species which are fragmentary than to recognize living plant species where complete specimens are available. It has occurred frequently that two fossil leaf forms have been described as representing two distinct species and similar forms were later found connected on one single branch. Such fossils as show characteristic differences and have never, been found to have grown on one and the same plant should be considered as different species. If we keep in mind the pronounced polymorphism of many organs in living plants, and assume that similar conditions prevailed in the Paleozoic era, we must conclude that our species distinctions of fossil plants are only approximately true and subject to constant revision upon the discovery of more complete material. It also follows that the better known species present a wider range of variations than those of which we know little. Furthern~ore,we know most fossil plant species only from impressions and PENNSYLVANIAP~ FLORA OF NORTHERN ILLINOIS 13

must base our species descriptions on few and often secondary characters. We have form types of this case-such as, stem types, leaf types, and fructification types. Only in comparatively few instances do we possess petrefacts with well preserved tissues and, under favorable circumstances, can we establish phylogenetic, that is, evolutionary relations and distinctions. Under such favorable but rare circumstances we actually have biological species types of the same value as offered by living plants. The plants that are figured in this report fall under the following general groups : 1. Equisetales 2. Sphenophyllales 3. Lycopodiales 4. Filicales 5. Cycadofilicales 6. Cordaitales Groups 1 to 4 inclusive belong to the general phylum of Pteridophytes, while groups 5 and 6 belong to the Gymnosperms of the Spermatophytes. No Angiosperm impressions were recognized in the Paleozoic era, although they probably existed, because Angiosperm-like structures were found in coal balls from the Pennsylvanian of Illinois1. The six groups mentioned above, with the exception of the Filicales, represent truly phylogenetic divisions of the plant kingdom. Originally all fern-like fossil leaves were classed as true ferns until many of them were found connected with Gymnosperm-like seeds. Early in the twentieth century the Cycadofilicales or seed fern group was established and was joined to the Gymnospel-nis. Since in most cases we deal with fern-like leaf impressions which may phylogenetically belong either to Pteridophy- tes or Gymnosperms, the most convenient form of classification may be Filicales or, as Potonik had suggested, Pteridophylls. As the latter name has not yet been introduced in this country, we may still be permitted to call the group Filicales, but it must be kept in mind that the fossils classified under this name are only a form group, an assemblage of leaf types, which may belong to true ferns or to seed ferns or, in some instances, to both.

The following forms, classified according to the various groups, were found in northern Illinois and are illustrated in Plates I to XLV: Equisetales: Calamites sucltowi Brongniart Annularia stellata (Schlotheim) Ib7ood A. radiata (Brongniart) Sternberg A. sphenophylloides (Zenker) Gutbier Calamocladus equisetiformis (Schlotheim) Schimper Calamostachys solmsi (Weiss) VVeiss C. germanica Weiss C. magna Lesquereux

'Hoskins. J. H.. A Paleozoic Xnpioiccerm from an American ccal hall; Botanical Gazette: p~.390-397,1923 Nof, A. C.,.A Paleozoic Angiosperm; Journal of Geolog>-:x-01. sxi. So. 4, sp. 344-347. 1923. 14 PENNSTLVSNIAN FLORA OF NORTHERN ILLINOIS

Sphenophyllales: Sphenophyllum emarginatum (Brongniart) Koenig S. majus (Bronn) Bronn Lycopodiales: Lepidodendron lanceolatum Lesquereux L. latifolium Lesquereux L. wortheni Lesquereux L. rigens Lesquereux Lepidophyllum majus Brongniart Lepidostrobus communis Lindley and Hutton Lepidostrobus ovatifolius Lesquereux Lepidophloios protuberans Lesquereux Lycopodites meekii Lesquereux Syringodendron porteri Lesquereux Sigillaria camptotoenia (Wood) Wood S tigmaria ficoides (Sternberg) Brongniart Filicales: 1. Sphenopteridae : Sphenopteris gracilis (Brongniart) Presl S. capitata White S. chaerophylloides (Brongniart) Presl Palmatopteris furcata (Brongniart) Potonik 2. Megalopteridae : Megalopteris southwellii Lesquereux 3. Mariopteridae: Mariopteris muricata (Schlotheim) Zeiller Mariopteris muricata var. nervosa (Schlotheim) Zeiller Mariopteris mazoniana (Lesquereux) White 4. Neuropteridae : Neuropteris rarinervis Bunbery Cyclopteris orbicularis Brongniart Neuropteris flexuosa Sternberg N. clarksoni Lesquereux N. ovata Hoffmann N. crenulata Brongniart N. capitata Lesquereux N. oblongifolia Gutbier N. vermicularis Lesquereux N. decipiens Lesquereux 5. Linopteridae : Linopteris neuropteroides (Gutbier) Potonie 6. Pecopteridae : Pecopteris vestita Lesquereux P. pseudovestita White P. lniltoni Artis P. squamosa Lesquereux PENNSYLVANIAN FLORA OF NORTHERN ILLINOIS

P. arborescens (Brongniart) Sternberg P. pennaeformis (Brongniart) Sternberg P. dentata Brongniart P. unita Brongniart Ptychocarpus unita (Brongniart) Weiss 7. Odontopteridae : Odontopteris subcuneata Bunbery 0. wortheni Lesquereux 8. Alethopteridae : Alethopteris serlii (Brongniart) Goeppert A. davreuxi (Brongniart) Goeppert A. grandini (Brongniart) Goeppert 9. Callipteridae : Callipteridium sullivanti (Lesquereux) Weiss 10. Fern stems: Megaphyton spec. Ptychopteris spec. Cycadofilicales and Cordaitales: Staphylopteris sagittatus Lesquereux Codonotheca caduca Sellards Codonospermum anomalum Brongniart Tripterospermum rostratum Brongniart Trigonocarpum noeggerathi Sternberg Pachytesta incrassata Brongniart Cardiocarpus orbicularis Ettingshausen Cordaitales: Cordaites grandifolius Lesquereux Cordaianthus gemmifer Grand ' Eury

DISCUSSION OF FIGURED ORDERS AND GENERA EQUISETALES The Paleozoic Equisetales, remnants of which are preserved, must have been arborescent forms. Undoubtedly, herbaceous species, from which our modern Equisetum descended, must also have existed. The name, Calamites, always designates a stem form. Independently, leaves and smaller branches were found which were called Annularia or Calamocladus and fructifications, which were named Calamostachys. These are, therefore, not biological genus names but form types, because a Calamites, an Annularia, and a Calamostachys grew on the same individual plant. How- ever, it is not known, except in very few instances, which species of these genera belonged together. For practical purposes, particularly for use as stratigraphic index fossils, it is immaterial to know how they were com- bined. The biological paleobotanist or, better called, fossil plant morpholo- gist w-ould, of course, like to know more of these combinations in order to explain the phylogeny of the Paleozoic Equisetales, but in order to study this aspect with hope of success it will be necessary to obtain a great deal more material, especially petrified or coal ball specimens. I6 PENKSPLVANIAN FLORA OF NORTHERN ILLINOIS

This order contains only one genus, Sphenophyllum, and that is now extinct. We know nothing about any relation of the Paleozoic Sphenophyl- lales with living plants. Sphenophyllum was an aquatic and herbaceous plant, had jointed stems with whirls of triangular leaves that always appeared in multiples of three. At the end of the branches were the long and narrow strobili.

Probably most of the known genera and species of fossil Lycopodiales were arborescent, with the exception of the genus Lycopodites, which was herbaceous. There must have been numerous herbaceous Lycopodiales in the Paleozoic era from which our living Lycopodiales descended. The large tree forms died out almost entirely at the end of the Paleozoic era, but a few medium-sized Mesozoic tree types persisted for a short time. The two principal genera of the Paleozoic era are Lepidodendron and Sigillaria, both of which reached a height of about one hundred feet. Lepidodendron is the generic name for a stem type that had spirally arranged rhomboidal leaf scars, whereas Sigillaria had its leaf scars ver- tically arranged. Syring-odendl-on was a Sigillaria whose cortex had been removed before fossilization. Lepidostrobus is the generic name for the strobilus or cone of Lepidodendron. Lepidophyllum is the scale of Lepido- strobus, and Stigmaria designates a root form that might have belonged to a Lepidodendron or a Sigillaria stem. The different species of Lepidoden- dron and Sigillaria are distinguished by the shape of their leaf cushions. Leaves seem to have been born only on the youngest bsanches of these trees, but the leaf cushions continued to grow on the stem and on the older branches after the leaves had fallen off and formed a sort of armor around the tree similai- in function to the armor of some living Cycads but differing in the shape of their leaf scars. The leaf scars of Lepidophloios were more broad than long, whereas those of Lepidodendron were more long than broad. Lycopodites was a herbaceous type, similar to the modern genera Selaginella and Lycopodium. The root form of Lepidodendson and Sigillaria, Stigmaria ficoides, was covered with small rootlets of which the circular scars are still visible.

The maqt numerous and stratigraphically most useful plant fossils of the Paleozoic sediments are impsessions of fern-like leaves. A largc number, perhaps the majority of them, did not belong to true ferns bul were parts of trees that had the habitus of tree ferns and the fructifications of Gymnosperms. This extinct group which seemed to have sprung from the same origin as the true ferns has been disco-\-erccl only during the earl!. twentieth century and in Xniericn is called Cycadofilicales. English paleobotanists use the name Pteridospernic, a Gr~ektranslation for seed- ferns. The fructifications of these Cycadofilicales will be discussed later. PENNSYLVANIAN FLORA OF NORTHERN ILLINOIS 17

As mentioned in an earlier chapter, the group name Filicales is still used in this report for the fern-like impressions. For two very characteristic fern stem types the generic names of Megaphyton and Ptychopteris are used. They are marked by very large leaf scars which were produced after the leaf stems or petioles had fallen off. The fern-like leaves are divided into genera according to the following characters : a. The form of attachment of the smallest leaf units (pinnules) to the stem that bears them. b. The general shape of the pinnules and their arrangement and de- velopment in the fronds. c. The venation of the pinnules. On the basis of these distinctions we have arranged our material into the following genera : 1. Sphenopteris. The pinnule is contracted at its base and is lobed or dissected. Some Sphenopteris species were Cycadofilicales. 2. Palmatopteris. This genus resembles Sphenopteris but has very deeply dissected pinnules. It is a Cycadofilicales. 3. Megalopteris. This is a large-leafed fern type with a simple pin- nate frond and was probably herbaceous. It is rarely found and occurs only in the Pottsville formation. It is present in the Rock Island district. It is a Cycadofilicales. 4. Mariopteris. This genus has a large frond that is divided many times. Its pinnules have a broad base and arch-shaped secondary veins projecting from the base of the pinnule. Frequently no midrib is visible. It is a Cycadofilicales. 5. Neuropteris. Pinnules have a narrow base from which arch-shaped veins emerge. There is usually a midrib. The veins fork dichotomously from one to several times but are not connected. At the base of the com- posite frond are rounded leaves with a radiating venation. These leaves were originally called Cyclopteris and were considered as belonging to a distinct genus. For the sake of convenience, this name has been retained to characterize such types of leaves. 6. Linopteris. The shape of the pinnule is exactly like that of Neurop- teris, but the veins are anastomosed and form a net. It is a Cycadofilicales. 7. Pecopteris. A large number of species belong to this genus which is especially well represented in the higher strata of the Pennsylvanian. The pinnules are generally small and possess a distinct midrib usually with few secondary veins and a broad base. The name Asterotheca and Ptycho- carpus are used for certain Pecopteris forms which show spore capsules. 8. Odontopteris. This genus has a pinnule like Pecopteris except that there is no midrib and the veins enter parallel from the base. It is a Cycado- filicales. 9. Alethopteris. The pinnules also have a broad attachment, but their bases are decurrent. The midrib is always very distinct and the secondary veins numerous. It is a Cycadofilicales. 18 PENNSYLV-4NIAN FLORA OF NORTHERN ILLINOIS

10. Callipteridium. This differs primarily by its broad, bluntly ending pinnules from Alethopteris. In Europe Callipteridium is an index fossil of Permian and Sub-Permian strata. It is a Cycadofilicales. Some basal leaves of fern-like fronds are called Aphlebiae. Sometimes young leaves which are still coiled are found. Although the generic name, Spiropteris, is well suited to these forms, it seems rather useless to distinguish species, for every individual fossil of this kind would have to re- ceive a species name. The only true ferns (Filicales) among the leaf impressions found at Mazon Creek and Braidwood belong to the genera Sphenopteris and Pecopteris.

Numerous seeds of gymnospermic character but associated with fern- like leaves, such as Codonospermum, Tripterospermum, Pachytesta, Stephanospermum, Trigonocarpum are known. Codonotheca, which was first found by E. H. Sellards in Illinois and described by him, is probably a microspore-bearing organ of Neuropteris. Staphylopteris may have had the same function but was associated with Sphenopteris.

These were gymnospermic trees with tall shafts whose branches bore tufts of very large ribbon-shaped leaves. The male reproductive organs of this order received the generic name of Cordaianthus, the female, that of Cardiocarpus, and the leaves that of Cordaites. PART 11.-EXPLANATION OF PLATES

Note: Objects are reproduced in natural size except where otherwise indicated.

ABBREVIATIONSFOR COLLECTIONS U C Col1.- Collection in Walker Museum of the Uni- versity of Chicago U I Col1.- Collection in the Museum of Natura His- tory, University of Illinois K Col1.- Collection of Wilbur T. Knoblock, 1901 Ohio St., Quincy, Illinois C Col1.- Collection of George Condie, 320 E Erie St., Spring Valley, Illinois

PLATE 11. EQUISETALES

The surviving genus of this great Paleozoic order is Equisetum, a herbaceous plant growing along creeks and in damp meadows. It is commonly called Horse Tail or Scouring Rush. In Pennsylvanian times tree forms of this order grew. Their stems are called Calamites, their leaves Annularia, or if smaller and more numerous Calamocladus, their fructifications Calamostachys. (See Plates I1 to V.)

1. CALAMITESSUCKOTVI Brongniart, from La Salle, x 1/5, U C Coll. No. 32000.

2. CALAMOSTACHYSSOLMSI (WEISS)Weiss, from Braidwood, U C Coll. No. 32001.

3. CALAMITESSUCKOWI Brongniart, from Braidzoood, x 2/3 U C Coll. No. 32002.

PLATE111. EQUISETALES

1-5. ANNULARIASTELLATA (Schlotheim) Wood. 1,2, and 4. From Mazon Creek, U. C. Coll. No. 32003. 3 and 5. From Braidwood, U I Coll. No. P 1281.

PLATEIV. EQUISETALES

T 1. CALAMOCLADUSEQUISETIFORMIS (~ch1otheim)JSchirnper, from Morris, Ill., x 2/3, U I Coll. No. P 1282.

2. ANNULARIAKADIATA (Brongniart) Sternberg. On branches of a Calamites stem, from iWazo~Creek, x 2/3, U I Coll. No. P 1283.

PLATEV. EQUISETALES

1. ANNULARIARADIATA (Brongniart) Sternberg, from Mazon Creek, U C Coll. No. 32004.

2. ANNULARIASPHENOPHYLLOIDES (Zenker) Gutbier, from Mazon Creek, U C Coll. No. 32005.

3. ANNULARIASPHENOPHYLLOIDES (Zenker) Gutbier, from Braidwood, U C Coll. No. 32006.

4. CALAMOSTACHYSGERMAKICB Weiss (The strobilus of Calamocladus equisetiformis Schl.), from Byaid-wood, U C Coll. No. 3200'7.

5. CALAMOSTACHYSMAGNA Lesquereus, from Mazon Creek, x 2/3 U I Coll. No. P 1284.

PLATEVI. SPHENOPHYLLALES

These grew in brooklets and had floating stems and wedge-shaped leaves as denoted by the Greekname Spheno- phyllum. No living relatives of this Paleozoic plant order are known.

1. SPHENOPHYLLUMMAJUS (Bronn) Bronn, from Mazon Creek, U C Coll. No. 32008.

2. SPHENOPHYLLUMSTEM, from Braid,wood, x 2/3, U C Coll. No. 32009.

3-6. SPHENOPHYLLUMEMARGINATUM (Brongniart) Koenig, from Braid- wood, U C Coll. No. 32074, No. 32089, and No. 32090.

PLATEVII. LYCOPODIALES

The surviving genera of this order are our present day club mosses Lycopodium and Selaginella. From the Penn- sylvanian are known tree forms Lepidodendron, Lepido- phloios, and Sigillaria, and a herbaceous type Lycopodites. S~ringodendronis the name for a Sigillaria type which had lost its characteristic bark before fossilization. Lepi- dostrobus is the fructification of Lepidodendron. Stig- maria is the name for the roots of Lepidodendron and Sigillaria. (See Plates VII to XII.) 1. ~d~~~~os~~o~usOVATIFOLIUS Lesquereux (cone of Lepidodendron).

2. LEPIDODENDROSLANCEOLATUM Lesquereux.

3. LEPIDOSTROBUSCOMMUNIS Lindley and Hutton.

4. LEPIDODENDRONLATIFOLIUM Lesquereux. All are from ilfaaon Creek, K Coll. ILLINOISSTATE GEOLOGICAL SURVE~ BULLETINNO. 52, PLATEVIE PLATEVIII. LUCOPODL4LES

1. LEPII)OPI-II,OIOSPROTUBERANS Lesquereux, from Braidwood, U C Coll. No. 32010. 2. LEPIDODENDRONWortheni Lesquereux, from Mazo7z Creek, U C Coll. No. 32011.

3. LEPIDODENDRONLATIFOLIUM Lesquereux, from Mazorz Creek, U C Coll. No. 32011. ILLINOISSTATE GEOLOGICAL SURVEY BULLETINNO. 52, PLATEVIII PLATEIX. LYCOPODIALES

LEPIDODEWDRONRIGEKS Lesquereux, from Mazon Creek, U C Coll. No. 32013.

PLATEX. LYCOPODIALES

1. LYCOPODITESMEEKII Lesquereux, from Mazon Creek, U I Coll, No. P 128.5.

2-3. LEPIDOPHYLLUMMAJUS Brongniart, from Mazo~z Creek, x 2/1, U C Coll. No. 32014. 4. LYCOPODITESMEEKII Lesquereux, from Mazon Creek, x 2/3, U C Coll. No. 32015.

PLATEXI, LYCOPODIALES

1. SIGILLARIACAMPTOTAENIA (Wood) Wood, from Braidwood, U C Coll. No. 32016.

2. SYRINGODENDRONPORTERI Lesquereux, from Braidwood, x 112, U C Coll. No. 32017.

3. SIGILLARIACAMPTOTllENIA (1v00d) 1v00d, from Braidwood, U C Coll. No. 32018.

PLATEXII. LYCOPODIALES

1-3. STIGMARIAFICOIDES (Sternberg) Brongniart, from Braidwood, x 2/3, U C Coll. No. 32019, No. 32079, and No. 32080.

PLATEXIII. FILICALES: SPHENOPTERIDAE

Here belong such leaf impressions as might have grown on true herbaceous fern plants, on tree-ferns, and on so- called seed-ferns or Cycadofilicales. The latter are an extinct type of Gymnosperms with fern-like foliage and cycad-like fructifications. They formed a link between ferns and cycads in evolution. In this publication all fern- like leaves are listed under Filicales and all Cycadofilicales- seeds under Cycadofilicales. Stems of true ferns were found and are pictured in this bulletin under the generic names Megaphyton and Ptychopteris. (See Plates XI11 to XIV.)

1. PALMATOPTERISFURCATA (Brongniart) Potoniit, from Braidwood, U C Coll. No. 32020.

2. SPHENOPTERISGRACTLIS Brongniart, from hfazon Creek, U C Coll. No. 32021.

3. SPHENOPTERISCAPITATI White, from Braidwood, U C Coll. No. 32022.

PLATEXIV. FILICALES: SPHENOPTERIDAE

SPHENOPTERISCHAEROPHYLLOIDES (Brongniart) Presl, from Mazon C~eek,U C Coll. No. 32023. BULLETINNO. 52, PLATEXIV PLATEXV. FILICALES : MEGALOPTERIDAE

MEGALOPTERISSOUTHWELLII Lesquereux, from Port Byron, Collec- tion of Davenport (Iowa) Academy of Science.

PLATEXVI. FILICALES : MARIOPTERIDAE

1. R~ARIOPTERIS MURICATA VAR. NERVOSA (Schlotheim) Zeiller, from Mazon Creek, U C Coll. No. 32024.

2-3. MARIOPTERISMURICATA (Schlotheim) Zeiller, from Mazon Creek, U I Coll. No. P 1286 and No. P 1317.

4. MARIOPTERIS MAZONIANA (Lesquereux) White, from BraicE-dood, U C Coll. No. 32025.

5. R~AIIIOPTERIS MURICATA VAR. NERVOSA (Schlotheim) Zeiller, from Braidwood, U C Coll. No. 32081. ILLINOISSTATE GEOLOGICAL SURVEY BULLETINNO. 52, PIATEXVI PLATEXVI I. FILICALES : NEUROPTERIDAE

1-3. NEUROPTERISRARIXERVIS Bunbery. 1. Frorn Spring Valley, x 1!2, C Coll. 2. From Mazon Creek, x 2/3;U I Coll. No. P 1287. 3. From Spring Valley, s 1/3, C Coll. ILLINOISSTATE GEOLOGICAL SURVEY BULLETINNO. 52, PLATEXVII PLATEXVIII. FTLICALES : NET_JROPTERIDAE

1-3. NEUROPTERISRARINERVIS Bunbery. 1. From Mazon Creek, U C Coll. No. 32088. 2. From Mazon Creek, x 112, U I Coll. No. P 1288. 3. From Braidwood, U C Coll. No. 32026. ILIJNOISSTATE GEOLOGICAL SURVEY BULLETINNO. 52, PIATE XVIII PLATEXIX. FILICALES : NEUROPTERIDAE

1-2. CYCLOPTERISORBICULARIS Brongniart, from Braidwood, U C Coll. No. 32027 and No. 32082. BULLETINNO. 52, PLATEXIX PLATEXX. FILICALES : NEUROPTERIDAE

1. NEUROPTERISFLEXUOSA Sternberg, from iiazon Creek, U C Coll. No. 32028.

2. NEUROPTERISCLARKSONI Lesquereux, from iWazon Creek, s 2/3, U C Coll. No. 32029.

3. NEUROPTERISOVATA Hoffmann, from Mazo~z Creek, U C Coll. No. 32030.

PLATEXXI. FILICALES: NEUROPTERIDAE

1. NEUROPTERISCLARKSOSI Lesquercux, from Mnzon Creek, x 1/2, U C Coll. No. 32031.

2-3. NEUROPTERISFLEXUOSA Sternberg, from Mazon Creek, x 2/3, U C Coll. No. 32032 and No. 32083.

4. NEUROPTERISOVATA Hoffman, from Mazon Creek, x 2/3, U I Coll. No. P 1289. 5. NEUROPTERISCRENULATA Brongniart, from Mazo~zCreek, x 21.3, U I Coll. No. P 1290. ILLINOISSTATE GEOLOGICAL SURVEY BULLETIXNO. 52, PLATEXXI PLA~XXII. FILICALES : NEUROPTERI DAE AND LINOPTERIDAE

1-3. NEUIIOPTERISCAPITATA Lesquereux. 1. Ultimate pinnule from Mason Creek, U I Coll. No. P 1291. 2-3. From iWazon Creek, U C Coll. No. 32033 and No. 32084.

4. LINOPTERISNEUROPTEROIDES (Gutbier) Potonik, from Mazon Creek, U I Coll. No. P 1292. ILI.INOISSTATE GEOLOGICAL SURVEY BULLETINNO. 52, PLATEXXII PLATEXXI 11. FILICALES : NEUROPTERIDAE AND LINOPTERIDAE

1. LINOPTERISNEUROPTEROIDES (Gutbier) Potonik, from Mazon Creek, U I Coll. No. P 1293.

2. NEUROPTERISOBLONGIFOLIA Gutbier, from Ma'kon Creek, U I Coll. No. P 1294.

3. NEUROPTERISFLEXUOSA Sternberg, from Mazon Creek, K Coll. BULLETIXNO. 52, PLATEXXIII PIATEXXIV. FILICALES: NEUROPTERIDA4E

1. NEUROPTERISVERMICULARIS Lesquereux, from Mazon Creek, x 514, K Coll.

2-4. NEUROPTERISDECIPIENS Lesquereux. 2. From Mazon Creek, s 2/5, U I Coll. KO. P 1296. 3. From Braidwood, U C Coll. No. 32034. 4. From Mazon Creek, x 312, U C Coll. Yo. 32035. BULLETINNO. 52, PLATEXXIV PLATEXXV. FILJCALES: NEUROPTERID-IE

1-3. NEUKOPTEKISnEcmms Lesquere~~s. 1. From Braidwood, U C Coll. No. 32035. 2-3. From Mazorz Creek, x 21'5, I< Coll.

PLATEXXVI. FILICALES : NEUROPTERIDAE

1-4. NEUROPTERISDECIPIEKS Lesquereux. I. Cyclopteroid leaf, from Mazon Creek, x 6;'5, U I Coll. KO. P 1297. 2. From Mazon Creek, x 9/10, U I Coll. No. P 1298. 3. Cyclopteroid leaf, from &fazon Creek, U C Coil. No. 32036. 4. From Mazon Creek, U I Coll. No. P 1299. ILLINOISSTATE GEOLOGICAL SURVEY BULLETINNO. 52, PLATEXXVI PLATEXXVII. FILICALES : NEUROPTERIDAE

1-2. NEUROPTERISDECIPIENS 1,esquereus. 1. From Mazon Creek, K Coll. 2. From Mazon Creek, x 3/2, K Coll.

3. NEIJKOPTERISRARINERVIS Bunbery, Cycloperoid leaf, iron1 Bmid- wood, x 6/5, U C Coll. No. 32037. ILLINOISSTATE GEOLOGICAL SURVEY BULLETINNO. 52, PLATEXXVII PLATEXXVIII. FILICALES : VARIOUS LEAF TYPES

1. Aphlebia leaf.

2. NEUROPTERISDECIPIENS Lesquereux. Cyclopteroid leaf. 3-12. Spiropteris leaves, young and rolled leaves.

5. NEUROPTERISDECIPIENS Lesquereux, Cyclopteroid leaf. All from Mazon Creek, U C Coll. No. 32038-42. ILLINOISSTATE GEOLOGICAL SURVEY BULLETINNO. 52, PLATEXXVIII PLATEXXIX. FILICALES: PECOPTERIDAE

1. PECOPTEKISYSEUDOVESTITA White, from Mnzort Creek, U C Coll. No. 32043.

2. PECOPTERISVESTITA Lesquereux, from Mazotz Creek, U C C'oll. No. 32044.

3. PEC~PTERI~VESTIT.\ Lesquereux, from Mnzon Creek, x 1/2, U C Coll. No. 32045. ILLINOISSTATE GEOLOGICAL SURVEY BCLLETINNO. 52, PLATEXXIS PLATEXXX. FILICALES : PECOPTERIDAE

1. PECOPTERISXILTOXI Artis, from Mnzon Creek, U C Coll. No. 32047.

2. PECOPTERISVESTITA I,esquereux, from iWazon Creek, U I Coll. 50.P 1301.

3. PECOPTERISSQUAMOSA Lesquereux, from iWosolz Creek, U I Col!. No. P 1302.

PLATEXXXI. FILICALES: PECOPTERIDAE

1-2. PECOPTERISARBORESCENS (Brongniart) Sternberg from Mazon Creek, U I Coll. No. P 13034. ILLINOISSTATE GEOLOGICAL SURVEY BULLETINso. 52, PLATEXXXI PLATEXXXII. FILICALES: PECOPTERIDAE

PECOPTERISPENNAEFORMIS (Brongniart) Sternberg, from Braidwood, U C Coll. No. 32048. BULLETINNO. 52, PLATEXXXII PLATEXXXIII. FILICALES: PECOPTERIDAE

PLATEXXXIV. FILICALES : PECOPTERIDAE

1. PECOPTERISUNITA Brongniart, from iUazon Creek, U I Coll. No. P 1300.

3. PECOPTERISMILTON Artis, from Mazon Creek, K Coll.

4. PECOPTERISMILTONI Artis, from Mazon Creek, U C Coll. No. 32046. ILLINOISSTATE GEOLOGICAL SURVEY BULLETINNO. 52, PLATEXXXIV PLATEXXXV. FILICALES: PECOPTERIDAE

1-2. PECOPTERISUKlT,4 Brongniart, from ~lfuzonCreek, U I Coll. No. P 1306-7. ILLINOISSTATE GEOLOGICAL SURVEY BLLLETIXNO. 52, PLATEXXXV PLATESSXVI. FILICALES: PECOPTERIDAE

1-4. PTYCHOCARPUSUNITA (Brongniart) Weiss, with sori. Nos. 1, 3, and 4. From Mazon Creek, U C Coll. No. 32049-51. No. 2. From iVazon Creek, x 211, U C Coll. No. 32087. BULLETIKNo. 52, PLATEXXXVI PLATEXXXVII. FILICALES: ODONTOPTEIIIDAE

1-2. ODOSTOPTERISSC'RCUNEAT.I Bunber\-, froni Mnzmz Creek, U C' Coll. No. 32052-3.

3-4. ODONTOPTERISWORTHEKI I,csquereux, from llfazon Creek, U C Coll. No. 32054-5.

PLATEXXXVIII. FILICALES: ALETHOPTERIDAE

1-2. ALETHOPTERISSEKLII (Brongniart) Goeppert, from Mazon Creek, U C Coll. NO. 32056-7.

3-4. ALETHOPTERISSERLII (Brongniart) Goeppert, from Braidwood, U C Coll. No. 32058-9. BULLETINNO. 52, PLATEXXXVIII PLATEXXXIX. FILICALES: ALETHOPTERIDAE

I. ALETHOPTERISDAVREUXI (Brongniart) Goeppert, from Mazotz Creek, U I Coll. No. P 1308.

2. ALETHOPTERI~SERLII (Brongniart) Goeppert, from Mazon Creek, U C Coll. No. 32060.

.?--I. ALETHOPTERISSERLII (Brongniart) Goeppert, from Mazon Creek, K Coll.

PLATEXL. FILICALES: ALETHOPTERI DM?

1-2. ALETHOPTERISGRANDINI (Brongniart) Goeppert, from Mazon Creek, U I Coll. No. P 1309-10.

PLATEXLI. FILICALES : CALLIPTERIDAE

1-4. CALLIPTERIDIUMSULLIVANTI (Lesquereux) Weiss. 1, 4. From Muzon Creek, U I Coll. No. P 1311-12. 2, 3. From Mazon Creek, U C Coll. No. 32061-2. ILLINOISSTATE GEOLOGICAL SURVEY BULLETINNO. 52, PLATEXLI PLATEXLII. CYCADOFILICALES : REPRODUCTIVE ORGANS

1-4. STAPHYLOPTERISSAGITTATUS Lesquereus, from Mazon Creek, U C Coll. No. 32063-6. BULLETINNO. 52, PLATEXLII PLATEXLIII. CYCADOFILICALES : REPRODUCTIVE ORGANS

1-3. CODOPI'OTHECACXDUCA Sellards, from Mazon Creek, x 2/ 1, IT 1 Coll. No. P 1313, P 1318, P 1319.

4. CODONOSPERMUMANOMALUM Brongniart, from Braidwood, U C Coll. No. 32067.

5. TRIPTEROSPERMUMROSTRATUM Brongniart, from Braidwood U C Coll. No. 32086. ILLINOISSTATE GEOLOGICAL SURVEY BULLETINNO. 52, PLATEXLIII PLATEXLIV. CYCADOFILTCALES AND CORDAITALES: REPRODUCTIVE ORGANS

1-2. TRIPTEROSPERMUMROSTRXTUM Brongniart, from Braidwood, U C: Coll. No. 32068.

3. CARDIOCARPUSORBICULARIS Ettingshausen, x 2/1, from Mazon Creek, K Coll.

4. PACHTTESTAINCRASSATA Brongnia~t,fro111 Braidwood, U C Coll. No. 32069.

5. TRIGONOCARPUMNOEGGERATHI Sternberg, from Mazon Creek, x 2/1, K Coll. BULLETINNo. 52, PLATEXLIV PLATEXLV. CY CADOFILICALES, CORDAITALES, AND FERN STEMS

An extinct class of Paleozoic Gymnosperms is named Cordaitales in honor of the great paleobotanist Corda. Leaves, stems, and the reproductive organs have been found. The leaves belong to the genus Cordaites, the male reproductive organs to Cordaianthus and the seeds to Cardiocarpus. Specimens are illustrated in Plate XLV, figs. 2 and 3.

1. STAPHYLLOPTERISSAGITTATUS Lesquereux, from Mazon Creek, K Coll.

2. CORDAITESCRANDIFOLIUS Lesquereux, from Muzon Creek, x 1/ 2, U C Coll. No. 32071. 3. CORDAIANTHUSGEMMIFER Grand ' Eury, from Mazon Creek, U C Coll. No. 32072. 4. MEGAPHYTONSPEC., from Braidwood, x 3/ 1, U C Coll. No. 32073.

5. PTYCHOPTERISSPEC., froin Coal City Willmington Sta.r Coal Mining Co., Mine No. 7, Y 3/ 1, Property of Mining Company. ILLINOISSTATE GEOLOGICAL SURVEY BULLETINNO. 52, PLATEXLV

INDEX

PAGE PAGE A Codonospermum ...... 18 Acknowledgn~ents...... 12 anomalum Brongniart .... .l5. 104-105 Alethopteridae ...... 15. 94-99 Codonotheca ...... 18 Alethopteris ...... 17 caduca Sellards ...... ISl 104-105 davreuxi (Brongniart) Goeppert .. Condie. George. fossils collected by . 10. 12 ...... 15,9 6-97 Cordaianthus ...... 18 grandini (Brongniart) Goeppert . . gemmifer Grand 'Eury ... .ISl 108-109 ...... 15.98-99 Cordaitales ...... 15. 18. 106-109 serlii (Brongniart) Goeppert ..... Cordaites ...... 18 ...... 15. 94-95? 96-97 grandifolius Lesquereux ... .l5. 108-109 Annularia ...... 15 Culver. H . E.. assistance of ...... 12 radiata (Brongniart) Sternberg... Cycadofilicales ....15. 16-17? 18. 102-109 ...... 13,26-29 Cyclopteris ...... 17 sphenophylloides (Zenker) Gut- orbicularis Brongniart ...... 14. 56-57 bier ...... 13. 28-29 stellata (Schlotheirn) Wood .. .13, 24-25 Aphlebiae ...... 18, 74 Asterotheca ...... 17 Daniels. L . E., fossils collected by . 10. 12 Dawson. William. work of ...... 10 De Wolf. F . W.. cooperation of .... 12

Baker. F . C.. cooperation of ...... lo. 12 Braidwood. fossils from vicinity of . . 9. Equisetales ...... 13. 15. 22-29 22-23? 24-25? 28-29. 30-31. 34-35! 40-45. 50-51. 54-57. 66-67> 68-69? 72-73? 82-83? 95-96. 104-1051 106- 107 Fern stems ...... 5 105-109 Filicales ...... 14. 16-18? 44-10_1 Fossil plants. classification of ...... I 1-12 identification of ...... 1 2-15 Calamites ...... 15 Fossil species, definition of ...... 1 2-13 suckowi Brongniart ...... 13. 22-23 Calamocladus ...... 15 equisetiformis (Schlotheim) Schimper ...... 13. 26-27 Historical review ...... ll0-1 Calamostachys ...... 15 germanica Weiss ...... 13. 28-29 magna Lesquereux ...... 13. 28-29 solmsi (Weiss) Weiss ...... 13. 22-23 Introduction ...... 9-12 Callipteridae ...... 15. 100-101 Callipteridium ...... 18 sullivanti (Lesquereux) Weiss ...... 15. 100-101 Kidston. R..work of ...... 11 Cardiocarpus ...... 18 Knoblock. W . J., fossils collected by .10. 12 orbicularis Ettingshausen . .l5. 106-107 Carr. Ed.. cooperation of ...... 12 Carr. J . C.. fossils collected by .... .lo. 12 Classification of fossil plants ...ll-12. 13 LaSalle. fossils from vicinity of ... .22-23 Coal City. fossil plants from mine Leighton. M . M.. cooperation of ... 12 near ...... 9 Lepidodendron ...... 16 fossils from vicinity of ...... 108-109 lanceolatum Lesquereux .....l4. 32-33 PAGE P.4GE latifolium Lesquereux . 14. 32-33. 34-35 ovata Hoffmann ...... l4, 58-59, 60-61 rigens Lesquereux ...... 14. 36-37 rarinervis Bunbery ... .l4, 52-55, 72-73 wortheni Lesquereux ...... 14. 34-35 vermicularis Lesquereux .....l4, 66-67 Lepidophloios ...... 16 protuberans Lesquereux .....l4. 34-35 Lepidophyllum ...... 16 Odontopteridae ...... 15. 92-93 nlajus Brongniart ...... 14. 38-39 Odontopteris ...... 17 Lepidostrobus ...... 16 subcuneata Bunbery ...... l5. 92-93 communis Lindley and Hutton . . wortheni Lesquereux ...... 15. 92-93 ...... 14, 32-33 Oswald. W..cooperation of ...... 12 ovatifolius Lesquereux ...... 14, 32-33 Lesley. J . P., work of ...... 11 Lesquereux. Leo. work of ...... 3, 10-11 Linopteridae ...... 14 Pachytesta ...... IS Linopteris ...... 17 incrassata Brongniart ...... 15. 106-107 neuropteroides (Gutbier) Potonik Pal~natopteris...... 17 ...... 14, 62-63.6 4-65 furcata (Brongniart) Potonii: . 14. 44-45 Location of area ...... 9-10 Pecopteridae ...... 14. 76-9 1 Lycopodiales ...... 14, 16, 32-43 Pecopteris ...... 17. 18 Lycopodites ...... 16 arborescens (Brongniart) Stern- meekii Lesquereux ...... 14, 38-39 berg ...... 15. 80-81 dentata Brongniart ...... IS. 84-85 iniltoni Artis ...... l4. 78-79. 86-87 pennaeformis (Brongniart) Stern- Mariopteridae ...... 14. 50-51 berg ...... 15, 82-83 Mariopteris ...... 17 pseudovestita White ...... l4. 76-77 inazoniana (Lesquereux) White . . squamosa Lesquereux ...... 14, 78-79 ...... 14, 50-51 unita Brongniart .....l5, 86-87, 88-89 muricata (Schlotheim) Zeiller .... vestita Lesquereux ... .l4. 76-77. 78-79 ...... 14,s0-51 Port Byron, fossils from ...... 48 muricata var . nervosa (Schlot- Ptychocarpus unita (Brongniart) heim) Zeiller ...... 14, 50-51 Weiss ...... 15. 90-9 1 Mazon Creek, fossils from vicinity Ptychopteris spec ...... l5, 17. 108-109 of ...... 9, 24-25, 26-27, 28-29, 30-31, 32-33, 34-39, 44-45, 46-47, 50-51, 52-53, 54-55, 58-67, 68-73, 74-81, 86-95, Sigillaria ...... 16 96-105, 106-107, 108-109 camptotoenia (Wood) Wood ..14. 40-41 Megalopteridae ...... 14, 48-49 Skinner mine. fossil plants from .... 9 Megalopteris ...... 17 Species. definition of ...... I 2-13 southwellii Lesquereux ...... 14, 48-49 Sphenophyllales ...... 14. 16. 30-31 Megaphyton spec ...... l5, 17, 108-109 Sphenophyllum ...... 16 Miller, S . A., work of ...... 11 emarginatum (Brongniart) Koe- Morris, fossils from vicinity of .... nig ...... 14. 30-31 ...... 9, 26-27, 84-85 majus (Bronn) Bronn ...... 14. 30-31 Sphenopteridae ...... 14. 4447 Sphenopteris ...... 17. 18 capitata White ...... 14. 44-45 Neuropteridae ...... 14. 52-75 chaerophylloides (Brongniart) Neuropteris ...... 17 Presl ...... 14. 46-47 capitata Lesquereux ...... 14, 62-63 gracilis (Brongniart) Presl ....l4. 44-45 clarlrsoni Lesquereux . .14. 58-59. 60-61 Spiropteris ...... 18. 74-75 crenulata Brongniart ...... 14. 60-61 Spring Valley. fossils from vicinity decipiens Lesquereux ...... 14. 66-75 of ...... 9. 10. 52-53 flexuosa Sternberg ...... Staphylopteris ...... 18 ...... 14, 58-59. 60-61. 64-65 sagittatus Lesquereux ...... oblongifolia Gutbier ...... l4. 64-65 ...... 15. 102-103. 108-109 PAGE 1 PAGE Stephanian, correlation of flora from 10 1 Tripterosperrnum ...... 18 Stephanospermum ...... 18 rostratum Brongniart...... 15, 104-105, 106-107 Stigmaria ...... 16 ficoides (Sternberg) Brongniart.. . W ...... 14,16,42-43 Walsh, W.E., specimens given by.. 12 Syringodendron ...... 16 IVhite, David, assistance Of ....3, 11, l2 porteri L~~~~~~~~~.. .14, 40-41 Wlmington Star mine, fossil plants from ...... 9 T Y Trigonocarpum ...... 18 noeggerathi Sternberg. ... .l5, 106-107 Young, C. D., fossils collected by. .lo, 12